2.2.3 Ensure dhcp server services are not in use

Information

The Dynamic Host Configuration Protocol (DHCP) is a service that allows machines to be dynamically assigned IP addresses. There are two versions of the DHCP protocol DHCPv4 and DHCPv6 At startup the server may be started for one or the other via the -4 or -6 arguments.

Unless a system is specifically set up to act as a DHCP server, it is recommended that the dhcp-server package be removed to reduce the potential attack surface.

Solution

Run the following commands to stop dhcpd.service and dhcpd6.service and remove dhcp package:

# systemctl stop dhcpd.service dhcpd6.service
# yum remove dhcp

-OR-

-IF- the dhcp package is required as a dependency:

Run the following commands to stop and mask dhcpd.service and dhcpd6.service :

# systemctl stop dhcpd.service dhcpd6.service
# systemctl mask dhcpd.service dhcpd6.service

Impact:

There may be packages that are dependent on the dhcp-server package. If the dhcp-server package is removed, these dependent packages will be removed as well. Before removing the dhcp-server package, review any dependent packages to determine if they are required on the system.

-IF- a dependent package is required: stop and mask the dhcpd.service and dhcpd6.service leaving the dhcp-server package installed.

See Also

https://workbench.cisecurity.org/benchmarks/15962

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6, 800-53|CM-7, CSCv7|9.2

Plugin: Unix

Control ID: 6a41f3795c53442744ae23fcde3301a0eda6c01b437b588aee847583aadaa424